So that’s what is inside your furnace… It’s most likely a clam shell heat exchanger. This one happens to be cracked. The top center eyelet of each heat exchanger has a crack of above and below it. The others are nearing failure. However, one crack is all it takes to condemn.

What’s wrong with a crack? In the modern furnace, the primary risks is a fire. Over time the crack will open and allow flames to hit the cabinet. The secondary risk is carbon monoxide poisoning. This scenario is less likely due to the pressure switches that monitor the negative pressure inside the heat exchanger. You’re more likely to get air from the blower inside the heat exchanger rather than flue gases escaping.
How do you prevent this type of failure? It all goes back to proper air flow. Your ducts should provide design air flow per the manufacturer’s recommendations.
Often, we find that the duct system needs to be modified to achieve desired air flow.
Second, you must change your air filter regularly. Although some filters state ‘Three Months”, it’s important to check them monthly. You may find that your system draws more dust and animal¬†hair than the filter can handle in three months.
Finally, regular furnace maintenance by a professional service company keeps your system operating properly. You should have your HVAC system serviced twice a year — once for heating and the other time for air conditioning.
Give us a call today for all of your heating and air conditioning needs in Southern Indiana or the Louisville area — VanKleef Heating and Air Conditioning, Inc. (812)280-0510.